← Latinum Institute Ecclesiastical Latin Reading Course
For the complete Latinum Institute course index, visit: https://latinum.substack.com/p/index
Fīō, fierī, factus sum ranks among the most theologically significant verbs in Ecclesiastical Latin. This irregular, semi-deponent verb means “to become,” “to happen,” or “to be made/done.” It functions as the passive voice of faciō (to make, to do) in the present system, while borrowing its perfect forms directly from faciō‘s passive.
The third-person singular present subjunctive fīat (”let it be done” or “let it become”) appears at the very threshold of Sacred Scripture: Fiat lux — “Let there be light.” This same form echoes through salvation history in the Blessed Virgin’s response to the Archangel Gabriel: Fiat mihi secundum verbum tuum — “Let it be done to me according to thy word.” We pray it daily in the Lord’s Prayer: Fiat voluntas tua — “Thy will be done.”
The perfect participle factum appears in the Johannine Prologue’s central proclamation of the Incarnation: Et Verbum caro factum est — “And the Word was made flesh.” The gradual for Palm Sunday and Good Friday intones: Christus factus est pro nobis obediens — “Christ became obedient for us.”
In this lesson, all forms of fīō will be explored through authentic texts drawn from Scripture, liturgy, and the Fathers of the Church.
FAQ: What does fīō mean in Latin?
Fīō is an irregular Latin verb meaning “to become,” “to happen,” “to be made,” or “to be done.” It serves as the passive of faciō and appears throughout Catholic liturgy, Scripture, and theology to express divine action, transformation, and the unfolding of God’s will.
Key Takeaways: -
Fīō expresses becoming, happening, and passive making -
The form fīat is central to creation theology and Marian devotion -
Factum est expresses completed transformation (the Incarnation) -
This verb connects human obedience with divine creative power
✾ ❦ ✾ ❦ ✾ ✾ ❦ ✾ ❦ ✾ ✾ ❦ ✾ ❦ ✾
Form IPA Pronunciation fīō /ˈfi.o/ fīs /fis/ fit /fit/ fīat /ˈfi.at/ fierī /fi.ˈe.ri/ factus /ˈfak.tus/ factum /ˈfak.tum/ facta /ˈfak.ta/
Note: In Ecclesiastical Latin, vowels are pure (as in Italian): a = /a/, e = /e/, i = /i/, o = /o/, u = /u/. The digraphs ae and oe are pronounced as /e/.
✾ ❦ ✾ ❦ ✾ ✾ ❦ ✾ ❦ ✾ ✾ ❦ ✾ ❦ ✾
1. Fiat let-it-be-done lux light
Fiat (/ˈfi.at/) let-it-be-done lux (/luks/) light
— Genesis 1:3
2. Et and facta made est was lux light
Et (/et/) and facta (/ˈfak.ta/) made est (/est/) was lux (/luks/) light
— Genesis 1:3
3. Verbum the-Word caro flesh factum made est was
Verbum (/ˈver.bum/) the-Word caro (/ˈka.ro/) flesh factum (/ˈfak.tum/) made est (/est/) was
— John 1:14
4. Fiat let-it-be-done mihi to-me secundum according-to verbum word tuum thy
Fiat (/ˈfi.at/) let-it-be-done mihi (/ˈmi.i/) to-me secundum (/se.ˈkun.dum/) according-to verbum (/ˈver.bum/) word tuum (/ˈtu.um/) thy
— Luke 1:38
5. Fiat let-it-be-done voluntas will tua thy
Fiat (/ˈfi.at/) let-it-be-done voluntas (/vo.ˈlun.tas/) will tua (/ˈtu.a/) thy
— Matthew 6:10
6. Christus Christ factus made est was pro for nobis us obediens obedient
Christus (/ˈkris.tus/) Christ factus (/ˈfak.tus/) made est (/est/) was pro (/pro/) for nobis (/ˈno.bis/) us obediens (/o.ˈbe.di.ens/) obedient
— Philippians 2:8
7. Omnia all-things per through ipsum him facta made sunt were
Omnia (/ˈom.ni.a/) all-things per (/per/) through ipsum (/ˈip.sum/) him facta (/ˈfak.ta/) made sunt (/sunt/) were
— John 1:3
8. Quid what fiet will-become de of me me
Quid (/kwid/) what fiet (/ˈfi.et/) will-become de (/de/) of me (/me/) me
— Terence, Heautontimorumenos IV.3.37, cited in Vulgate tradition
9. Factum done est it-was autem moreover in in diebus days illis those
Factum (/ˈfak.tum/) done est (/est/) it-was autem (/ˈau.tem/) moreover in (/in/) in diebus (/di.ˈe.bus/) days illis (/ˈil.lis/) those
— Luke 2:1
10. Ipse he-himself dixit spoke et and facta made sunt they-were
Ipse (/ˈip.se/) he-himself dixit (/ˈdik.sit/) spoke et (/et/) and facta (/ˈfak.ta/) made sunt (/sunt/) they-were
— Psalm 32:9 (Vulgate); Psalm 33:9 (modern numbering)
11. Genitum begotten non not factum made
Genitum (/ˈdʒe.ni.tum/) begotten non (/non/) not factum (/ˈfak.tum/) made
— Nicene Creed
12. Fit it-becomes ut that intellegamus we-understand mysterium the-mystery
Fit (/fit/) it-becomes ut (/ut/) that intellegamus (/in.tel.le.ˈɡa.mus/) we-understand mysterium (/mis.ˈte.ri.um/) the-mystery
— Ecclesiastical usage
13. Sic thus fiat let-it-be-done
Sic (/sik/) thus fiat (/ˈfi.at/) let-it-be-done
— Liturgical formula
14. In in similitudinem likeness hominum of-men factus made
In (/in/) in similitudinem (/si.mi.li.ˈtu.di.nem/) likeness hominum (/ˈo.mi.num/) of-men factus (/ˈfak.tus/) made
— Philippians 2:7
15. Fiant let-become luminaria lights in in firmamento firmament caeli of-heaven
Fiant (/ˈfi.ant/) let-become luminaria (/lu.mi.ˈna.ri.a/) lights in (/in/) in firmamento (/fir.ma.ˈmen.to/) firmament caeli (/ˈtʃe.li/) of-heaven
— Genesis 1:14
✾ ❦ ✾ ❦ ✾ ✾ ❦ ✾ ❦ ✾ ✾ ❦ ✾ ❦ ✾
1. Per through quem whom haec these omnia all-things bona good creas thou-createst
Per (/per/) through quem (/kwem/) whom haec (/ek/) these omnia (/ˈom.ni.a/) all-things bona (/ˈbo.na/) good creas (/ˈkre.as/) thou-createst
— Roman Canon
2. Fiat let-it-be-done pax peace in in virtute strength tua thy
Fiat (/ˈfi.at/) let-it-be-done pax (/paks/) peace in (/in/) in virtute (/vir.ˈtu.te/) strength tua (/ˈtu.a/) thy
— Psalm 121:7 (Vulgate); Psalm 122:7 (modern)
3. Fiat let-it-be-done misericordia mercy tua thy Domine O-Lord super upon nos us
Fiat (/ˈfi.at/) let-it-be-done misericordia (/mi.se.ri.ˈkor.di.a/) mercy tua (/ˈtu.a/) thy Domine (/ˈdo.mi.ne/) O-Lord super (/ˈsu.per/) upon nos (/nos/) us
— Psalm 32:22 (Vulgate); Psalm 33:22 (modern)
4. Usque even ad unto mortem death factus made est was obediens obedient
Usque (/ˈus.kwe/) even ad (/ad/) unto mortem (/ˈmor.tem/) death factus (/ˈfak.tus/) made est (/est/) was obediens (/o.ˈbe.di.ens/) obedient
— Philippians 2:8; Gradual for Palm Sunday
5. Mortem death autem moreover crucis of-the-cross
Mortem (/ˈmor.tem/) death autem (/ˈau.tem/) moreover crucis (/ˈkru.tʃis/) of-the-cross
— Philippians 2:8 (continuation)
6. Propter therefore quod which et also Deus God exaltavit exalted illum him
Propter (/ˈprop.ter/) therefore quod (/kwod/) which et (/et/) also Deus (/ˈde.us/) God exaltavit (/ek.sal.ˈta.vit/) exalted illum (/ˈil.lum/) him
— Philippians 2:9
7. Factum made est it-was silentium silence in in caelo heaven
Factum (/ˈfak.tum/) made est (/est/) it-was silentium (/si.ˈlen.tsi.um/) silence in (/in/) in caelo (/ˈtʃe.lo/) heaven
— Revelation 8:1
8. Hoc this facite do in in meam my commemorationem remembrance
Hoc (/ok/) this facite (/ˈfa.tʃi.te/) do in (/in/) in meam (/ˈme.am/) my commemorationem (/kom.me.mo.ra.tsi.ˈo.nem/) remembrance
— 1 Corinthians 11:24; Words of Institution
9. Qui who propter for nos us homines men et and propter for nostram our salutem salvation descendit descended de from caelis heavens
Qui (/kwi/) who propter (/ˈprop.ter/) for nos (/nos/) us homines (/ˈo.mi.nes/) men et (/et/) and propter (/ˈprop.ter/) for nostram (/ˈnos.tram/) our salutem (/sa.ˈlu.tem/) salvation descendit (/de.ˈʃen.dit/) descended de (/de/) from caelis (/ˈtʃe.lis/) heavens
— Nicene Creed
10. Et and incarnatus incarnate est was-made de from Spiritu Spirit Sancto Holy
Et (/et/) and incarnatus (/in.kar.ˈna.tus/) incarnate est (/est/) was-made de (/de/) from Spiritu (/ˈspi.ri.tu/) Spirit Sancto (/ˈsank.to/) Holy
— Nicene Creed
11. Ex from Maria Mary Virgine the-Virgin et and homo man factus made est was
Ex (/eks/) from Maria (/ma.ˈri.a/) Mary Virgine (/ˈvir.dʒi.ne/) the-Virgin et (/et/) and homo (/ˈo.mo/) man factus (/ˈfak.tus/) made est (/est/) was
— Nicene Creed
12. Fiat let-it-be Domine O-Lord cor heart meum my immaculatum spotless
Fiat (/ˈfi.at/) let-it-be Domine (/ˈdo.mi.ne/) O-Lord cor (/kor/) heart meum (/ˈme.um/) my immaculatum (/im.ma.ku.ˈla.tum/) spotless
— Psalm 118:80 (Vulgate); Psalm 119:80 (modern)
13. Et and habitavit dwelt in in nobis us
Et (/et/) and habitavit (/a.bi.ˈta.vit/) dwelt in (/in/) in nobis (/ˈno.bis/) us
— John 1:14 (continuation)
14. Sine without ipso him factum made est was nihil nothing
Sine (/ˈsi.ne/) without ipso (/ˈip.so/) him factum (/ˈfak.tum/) made est (/est/) was nihil (/ˈni.il/) nothing
— John 1:3
15. Quod which factum made est was
Quod (/kwod/) which factum (/ˈfak.tum/) made est (/est/) was
— John 1:3 (continuation)
✾ ❦ ✾ ❦ ✾ ✾ ❦ ✾ ❦ ✾ ✾ ❦ ✾ ❦ ✾
The Verb Fīō:
Fīō is classified as a semi-deponent verb: it has active forms in the present system but passive meaning. It supplies the missing passive forms of faciō (to make, to do) in the present, imperfect, and future tenses.
Principal Parts: -
fīō (I become/am made) -
fierī (to become/be made — present infinitive) -
factus sum (I became/was made — perfect, borrowed from faciō)
Key Forms: -
fīat (present subjunctive 3rd singular): “let it be done/become” — the most theologically significant form -
fit (present indicative 3rd singular): “it becomes/happens” -
fīet (future indicative 3rd singular): “it will become” -
factum est (perfect indicative 3rd singular neuter): “it was made/became”
Theological Significance:
The verb fīō bridges divine will and created reality. When God speaks Fiat lux, light becomes. When Mary speaks her Fiat, the Word becomes flesh. The single word encompasses both the command and its fulfillment, both the act of will and the transformation of being.
In the Creed, genitum non factum (”begotten, not made”) uses factum to distinguish the Son’s eternal generation from created things that are facta — made out of nothing. The Son is begotten of the Father’s substance; He was not factus as creatures are.
The gradual Christus factus est has been set to music by numerous composers throughout the centuries, most notably Anton Bruckner, whose 1884 setting (WAB 11) remains among the most performed motets of the Catholic choral repertoire. The text derives from Saint Paul’s Epistle to the Philippians (2:8-9) and expresses the mystery of the kenosis — Christ’s self-emptying obedience unto death.
This lesson is part of the Ecclesiastical Latin Reading Course published by the Latinum Institute. For the complete course, visit https://latinum.substack.com/p/index
✾ ❦ ✾ ❦ ✾ ✾ ❦ ✾ ❦ ✾ ✾ ❦ ✾ ❦ ✾
---